The major objectives of this project are the elucidation of the local environmental factors which influence the regional variation in growth of solid glial neoplasms and to relate these to the effectiveness of chemotherapeutic agents. Regional blood flow, cell proliferation and metabolism are being studied in solid glial neoplasms transplanted in experimental animals. The growth characteristics and metabolism of several lines of glial neoplasms maintained in vitro are being studied in relation to various environmental changes. The changes in sensitivity of the tumor cells to antineoplastic drugs as related to their growth characteristics and metabolic environment are also being investigated. Biochemical studies of the solid tumor include measurements of regional energy reserves.